Dragon Ball Z is written to be compatible with the M.D.C. world of Rifts and is on par in power level to Phase World. It is important to note that a Dragon Ball Z campaign will be different then one from the show. The power levels in the show are incredibly high, with characters, such as Goku and Vegita, spending years training their bodies to ever higher levels of power, players could conceivably do the same, but most likely they will not have that chance. However, even without years of dedicated training, characters will probably be quite powerful.
The conversion for Dragon Ball Z was not written to be used exclusively in the Dragon Ball
Z setting. So a lone character could be used from this conversion in an adventure set in
the Phase World / Three Galaxies area or a GM could attempt to recreate a section of the
Dragon Ball Z storyline. I have not provided that storyline because it is very long and can
be easily found online, such as at the main
Using this option, the characters attempt to recreate the storyline behind the Dragon Ball Z series, or possibly the storyline behind all three series, Dragon Ball, Dragon Ball Z, and Dragon Ball GT. The storyline involves powerful villians that pose a challenge to the characters and offers plenty of opportunities for side adventures. The three Dragon Ball series are divided into sagas, each of which are almost self-contained storyline that can last months or years in game time and often revovles around a single challenge that the heroes must overcome. Attempting to recreate even one of these sagas, especially one of the longer ones, could create a very fun campaign.
The Saiyans homeworld of Vegita was destroyed by Freiza, but it is known that some Saiyans survived and could be wandering the universe, it is entirely possible that one of these Saiyans, asleep in their transport pod, could have fallen through a dimensional rift and arrived anywhere that the GM would like the Saiyan to arrive. As the Saiyans have the ability to implant educational programs into their children, a character could emerge as a child or as an adult with all of the skills and abilities that a normal Saiyan would have. A lone Saiyan could then be used as part of a normal campaign with a group of other characters.
The Nameks are in a similar situation as the Saiyans. The Nameks' homeworld was devastated by a comet strike and in the years since then, the Nameks have launched a number of children into space in hopes of establishing colonies on other planets so their race can continue to survive. A Namek child could easily have been brought through a Rift and been raised anywhere in the megaverse. They, along with Saiyans, would make natural slaves and gladiators for the Splugorth and this could be a great way to introduce them into an ongoing campaign.